www.megadrum.info

Hi everyone. first, just wanna say thanks for creating MD, finally i can do e-drumming without busting my wallet

I am new here, and just ran through the schematics. i want to ask if each component (resistors, capacitors, etc...) need to have the exact specification. for example, resistor - 33 ohm, .25W, 1%

Do i really need to use that resistor , or i can use any other 33 ohm resisitor to put in the circuit?

your help is greatly appreciated

tech_3298 wrote:I am new here, and just ran through the schematics. i want to ask if each component (resistors, capacitors, etc...) need to have the exact specification.

The components should have the same nominal value, that is if you wish to follow the design. If not then some of the resistors can be substituted for those with different nominal values. Just make sure that you know what you're doing.

tech_3298 wrote:for example, resistor - 33 ohm, .25W, 1%

Do i really need to use that resistor , or i can use any other 33 ohm resisitor to put in the circuit?

.25W = 1/4W - that's max power dissipation. I think 1/8W (and even 1/16W) should also be fine for MD, but I didn't really go into power related computations for this project, so Dmitri might correct me here. 1% is the tolerance value. The smaller this value is, the better. Typically, a tolerance of 1% to 5% is OK for non-precision circuits.

I also suggest reading through this topic since it contains some component list related information.

Thanks! the link really cleared things up

in general, you can always safely go higher on tolerances and maximum ratings.
For example, a 470uf 16v 20% capacitor can always be substituted by a 470uf 50v 5% capacitor, and a 100ohm 1/4 watt 5% can always be substituted by a 100ohm 1/2 watt 1% resistor. So don't adjust the component value but you can adjust other values for the most part. For example, you wouldn't want to trade a 40A fuse for a 100A fuse, because you may then get overcurrent in your appliance that the 40A fuse would've protected it from.

You can usually also adjust component ratings (such as the ohms of a resistor or the farads of a capacitor) as long as you stay within a general area, but this is dependent on the circuit so you should try to avoid this unless it's absolutely necessary or you've asked the circuit designer (or you understand the schematics yourself and you know a substitution can be made).

One important thing to note is that you should still stay in the general family of the component, so you shouldn't replace an electrolytic capacitor with a ceramic one, for example, or a 1N4148 diode by a 1N4004 regular diode. They have different characteristics of operation that may be appropriate to the circuit (4148 diodes have really high switching frequencies, for example)

Hope that helps!